Abstract.
This paper presents a new nonlinear model which describes localized magnetohydrodynamic (MHD) modes in reversed-field pinch (RFP) experiments. To date, nearly all experimental and theoretical work in this area has relied on the use of Fourier decomposition of spatial variations as a function of time. Moreover, due to the complexity of this nonlinear problem, previous work has been restricted to the analysis of a relatively small number of modes. In contrast, the model studied in this paper, based on the damped-driven sine-Gordon (DDSG) equation, addresses the full nonlinearity, does not rely on Fourier decomposition, and does not require the range of the nonlinearity to be small. A specific consequence of working with the full nonlinearity is the existence of solitary waves in dispersive media. These solitary waves, a key part of the model, are used to describe the so-called slinky mode propagating in the plasma. A remarkable resemblance is seen between the waveforms obtained from experiments and the mathematical predictions of the new model.
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References
H.K. Ebraheem, J.L. Shohet, A.C. Scott, Phys. Rev. Lett. 88, 235003 (2002)
J.L. Shohet, B.R. Barmish, H.K. Ebraheem, A.C. Scott, Phys. Plasmas 11, 3887 (2004)
A.F. Almagri, S. Assadi, S.C. Prager, J.S. Sarff, D.W. Kerst, Phys. Fluids B 4, 4080 (1992)
J.S. Sarff, Phys. Fluids B 5, 2540 (1993)
S.C. Prager, A.F. Almagri, S. Assadi, J.A. Beckstead, R.N. Dexter, D.J. Den Hartog, C. Chartas, S.A. Hokin, T.W. Lovell, T.D. Rempel, J.S. Sarff, W. Shen, C.W. Spragins, J.C. Sprott, Phys. Plasmas 2, 1367 (1990)
R. Bartiromo, Plasma Phys. Control. Fusion B 41, 143 (1999)
R. Fitzpatrick, S.C. Guo, D.J. Den Hartog, C.C. Hegna, Phys. Plasmas 6, 3878 (1999)
R. Fitzpatrick, Phys. Plasmas 6, 1168 (1999)
C.C. Hegna, Phys. Plasmas 3, 4646 (1996)
R. Fitzpatrick, E.P. Yu, Phys. Plasmas 7, 3610 (2000)
R. Fitzpatrick, T.C. Hender, Phys. Fluids B 3, 644 (1991)
R. Fitzpatrick, Nucl. Fusion 33, 1049 (1993)
E. Lazzaro, M.F.F. Nave, Phys. Fluids 31, 1623 (1988)
K. Kusano, T. Tamano, T. Sato, Nucl. Fusion 31, 1923 (1991)
G.A. Navratil, C. Cates, M.E. Maule, D. Maurer, D. Nadle, E. Taylor, Q. Xiao, W.A. Reass, G.A. Wurden, Phys. Plasmas 5, 1855 (1998)
H. Zohm, A. Kallenbach, H. Bruhns, G. Fussmann, O. Kluber, Europhys. Lett. 11, 745 (1990)
A.K. Hansen, A.F. Almagri, D.J. Den Hartog, S.C. Prager, J.S. Sarff, Phys. Plasmas 5, 2942 (1998)
Y. Yagi, S. Sekine, H. Sakakita, H. Koguchi, K. Hayase, Y. Hirano, I. Hirota, S. Kiyama, Y. Maejma, Y. Sato, T. Shimada, K. Sugisaki, Fus. Eng. Design 45, 409 (1999)
Y. Yagi, H. Koguchi, A.J.B. Nelsson, T. Bolzonella, P. Zanca, S. Sekine, K. Osakabe, H. Sakakita, Jpn. J. Appl. Phys. 38, 780 (1999)
Y. Yagi, H. Koguchi, H. Sakakita, S. Sekine, Y. Maejima, J.A.B. Nilsson, T. Bolzonella, P. Zanca, Phys. Plasmas 6, 3824 (1999)
Y. Yagi, H. Sakakita, S. Sekine, H. Koguchi, S. Kiyama, T. Osakabe, Fus. Eng. Design 46, 47 (1999)
R. Bartiromo, T. Bolzonella, A. Buffa, G. Chitarin, S. Martini, A. Masiello, S. Ortolani, R. Piovan, P. Sonato, G. Zollino, Phys. Rev. Lett. 83, 1779 (1999)
A.K. Hansen, Ph.D. thesis, University of Wisconsin-Madison (2000)
S. Assadi, S.C. Prager, K.L. Sidikman, Phys. Rev. Lett. 69, 281 (1992)
R.J. La Haye, N. Carlstrom, R.R. Goforth, G.L. Jackson, M.J. Schaffer, T. Tamano, P.L. Taylor, Phys. Fluids 27, 2576 (1984)
Y. Yagi, H. Koguchi, H. Sakakita, S. Sekine, P.R. Brunsell, J.A. Malmberg, Phys. Plasmas 8, 1625 (2001)
T. Tamano, W.D. Bard, C. Chu, Y. Kondoh, R.J. LaHaye, P.S. Lee, M. Saito, M.J. Schaffer, P.L. Taylor, Phys. Rev. Lett. 59, 1444 (1987)
G.B. Whitham, Linear and Nonlinear Waves (John Wiley & Sons, New York, 1974), p. 527
T.A. Fulton, R.C. Dynes, Solid State Commun. 12, 57 (1973)
J.L. Shohet, The Plasma State (Academic Press, New York, 1971), p. 149
A.C. Scott, F.Y.F. Chu, S.A. Reible, J. Appl. Phys. 47, 3272 (1976)
T.A. Fulton, L.N. Dunkleberger, Appl. Phys. Lett. 22, 232 (1973)
P. Guret, IEEE Trans. Magnet. MAG-11, 751 (1975)
P.S. Lomdahl, O.H. Soerensen, P.L. Christiansen, Phys. Rev. B 25, 5737 (1982)
A.C. Scott, Nonlinear Science: Emergence and Dynamics of Coherent Structures, 2nd edn. (Oxford University Press, New York, 2003), p. 72
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Shohet, J. The sine-Gordon equation in toroidal magnetic-fusion experiments. Eur. Phys. J. Spec. Top. 147, 191–207 (2007). https://doi.org/10.1140/epjst/e2007-00209-5
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DOI: https://doi.org/10.1140/epjst/e2007-00209-5